The present invention relates to a temperature control method for a heating kiln, such as a tunnel kiln, shuttle kiln and the like, for heating products to be fired by a plurality of burners as heat sources.
With heating kilns as tunnel kilns, shuttle kilns and the like having a plurality of burners for heating products to be fired, in the past, the temperature in the kiln has been controlled by controlling outputs of the burners. In more detail, in order to control the temperature in the kiln, temperature detecting means for each of the burners is provided at one typical location whose temperature will be affected by heat flow from the burner. In this case, if the detected temperature with the detecting means is lower than a set temperature, the output of the burner is increased, while if the detected temperature is higher than the set temperature, the output of the burner is reduced until the detected temperature becomes equal to the set temperature. All the burners are controlled in this manner and it is assumed that the temperature in the kiln arrives at the set temperature.
In such temperature control of a kiln having a plurality of burners, the output of each burner being controlled on the basis of the temperature at only one typical point affected by heat flow from the burner, particularly in tunnel kilns and the like having a number of burners, the heat flow from one burner affects other temperature detecting means for controlling the outputs of the other burners, and thus the burners interfere with one another. Therefore, the outputs of the respective heat sources are unbalanced making it difficult to maintain the uniform temperature in the kiln at a set temperature. Accordingly, it is impossible to control the temperature in the kiln at an optimum temperature.